In the practice of certain disciplines concerned with the study of aquatic conditions and phenomena, sampling the water is frequently conducted for purposes of testing or analyzing the specimen or the environment from which the specimen was obtained. For example, in oceanography, samples are taken to study the chemical composition of oceanic waters, in pollution control, specimens are obtained and analyzed for purposes of detecting abnormal amounts of pollutants, and in marine biology and ichthyology, specimens of the aquatic environment often yield information related to biologic investigations.
Particularly, there has been a need for a mechanical device that can procure a sample of the water or other liquid at a predetermined location that is remote from the operator of such device. Thus, it is frequently desirable to obtain specimens at a specific depth or at a distant horizontal location that may be inaccessible or which the operator may wish to leave uncontaminated by his presence or the presence of a large vessel.
There have previously been in use liquid samplers for obtaining samples at a given depth. As illustrated in U.S. Pat. to Langguth No. 3,302,464 and U.S. Pat. to Puthoff, et al., No. 4,004,463, the apparatus typically employed consists essentially of a container having a remotely operable valve and a line or cable for lowering the device to a desirable depth and retrieving the device after procurement of the sample. The valves previously employed are often complicated mechanical systems which are opened to permit liquid to enter the container when the device arrives at the appropriate depth and closed to prevent liquid from escaping from the container during retrieval. Due to the complexity of the valves and the plurality of functional elements therein, the proper operation of the devices is not assured. Devices having valves dependent upon gravitational forces for operation, such as in U.S. Pat. to Bodman, et al., No. 3,277,723, wherein a weighted messenger is lowered down the cable to trigger the valve, cannot reliably function if, for example, currents in the water alter the vertical orientation so as to thwart the proper functioning of gravitationally activated elements. Similarly, other sampling devices, as in the above noted patent to Langguth, require physical contact with the bottom of the body of water to trigger the valve. Such structures limit the utility of the device with respect to sampling at varied depths.
A particular need for an inexpensive, functionally simple sampling device has arisen in the area of sport and competitive fishing. As studies have found, the material and chemical content of the water in an outdoor reservoir or moving body of water will vary according to conditions of the internal and surrounding environment, such as the concentration of vegetation and the intensity of sunlight. Furthermore, it has been found that fish of various species prefer certain water conditions, and specifically, that bass tend to migrate to those waters that are closest to a chemical content which is slightly alkaline. Experimental results have shown that bass can be found more often in waters having a pH approaching 7.5 to 7.9. It has therefore become the practice among some fishermen to measure the pH of the area to be fished before devoting time to actual fishing.
Devices previously in use for measuring pH in lakes or streams have typically been expensive and inaccurate. The inaccuracy predominantly results from the location of the measuring device with respect to the area to be fished, as when, for example, the device consists of a meter having a probe which is attached to the fisherman's boat while the area to be fished is close to a bank, over a submerged bar, or in some other inaccessible location. Thus, a sampling device that could be cast to the area to be fished, remotely controlled by the fisherman, and operated at selected depths would fulfill the need for a sufficiently accurate means for testing water conditions.
A convenient method of accomplishing remote control at selected depths is the employment of the principles of drag forces resulting when a body is moved through a fluid. As illustrated for example in the above noted patent to Puthoff, et al. and U.S. Pat. to Quist No. 2,615,340, the principle has been applied to sampling devices to operate a valve opening to the container. Thus, a quick pull on the line will impart motion to the device, induce a drag force in the opposite direction to that in which the line is pulled, and open the valve to permit ingress of liquid. The previous devices, however, typically employ a complex valve mechanism which is not amenable to consistent, proper, and reliable functioning. Furthermore, the manner in which these particular devices operate would appear to not permit the casting of the devices as is done in sport fishing, since triggered valves and weighted members would possibly be subject to premature operation upon casting or upon impact with the surface of the water.
It is accordingly an object of the present invention to provide a liquid sampling device that is suitable for obtaining a specimen from a large volume of the liquid and in a designated location therein.
Another object of the present invention is to provide a sampling device that is remotely operated and which is not dependent upon depth or gravitational conditions for operation. In this connection, it is also an object of this invention to provide an inexpensive device having a mechanically simple valve that permits consistent, workable performance.
It is a further object of the present invention to provide a sampling device that can be used in fishing to test the chemical composition of the area to be fished, where by casting the device to the area, the device can be operated from the remote location of the fisherman.